SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0edd96fbdec578728f5683594fbaa39c435f7806fbbfaf41e28b4b247ad85e9' 
  AND token = 'q7HdHCPvIVqf4/n1cqEXghPPnh+G3bKbor0JB3s5guo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}